xsl-transform

#!/usr/bin/env bash

SHAREDIR=$(cd $(dirname "$0") && pwd)

function log {
    echo >&2 "$(date +%T.%3N) $LEVEL ocrd-import - $1"
}
function critical { LEVEL=CRITICAL log "$1"; }
function error { LEVEL=ERROR log "$1"; }
function warning { LEVEL=WARNING log "$1"; }
function info { LEVEL=INFO log "$1"; }
function debug { LEVEL=DEBUG log "$1"; }

((BASH_VERSINFO<4 || BASH_VERSINFO==4 && BASH_VERSINFO[1]<4)) && critical "bash $BASH_VERSION is too old. Please install 4.4 or newer" && exit 2

name=$(basename $0)
if [[ "$name" =~ ^page- ]]; then
    type="PAGE-XML"
elif [[ "$name" =~ ^mets- ]]; then
    type="METS-XML"
else
    type="input"
fi
parameters=()
pretty=0
inplace=0
diff=0
while (($#)); do
    case "${1:--h}" in
        -h|-[-]help)
            cat <<EOF
Usage: $name [OPTIONS] [FILE]

with options:
 -s name=value    set param NAME to string literal VALUE (repeatable)
 -p name=value    set param NAME to XPath expression VALUE (repeatable)
 -i|--inplace     overwrite input file with result of transformation
 -P|--pretty      pretty-print output (line breaks with indentation)
 -d|--diff        show diff between input and output
 -D|--dump        just print the transformation stylesheet (XSL)
 -h|--help        just show this message

Open $input file FILE (or stdin) and apply the XSL transformation "$name.xsl"
Write the result to stdout, unless...
 -i / --inplace is given - in which case the result is written back to the
                           file silently, or 
 -d / --diff is given - in which case the result will be compared to the
                        input and a patch shown on stdout.
EOF
            exit
            ;;
        -s|-p)
            [[ "$2" =~ .*=.* ]] || critical "invalid parameter syntax '$2'"
            parameters+=( "$1" "$2" )
            shift
            shift
            ;;
        -D|--dump)
            cat "$SHAREDIR"/$name.xsl
            exit
            ;;
        -P|--pretty)
            pretty=1
            shift
            ;;
        -i|--inplace)
            inplace=1
            shift
            ;;
        -d|--diff)
            diff=1
            shift
            ;;
        *)
            break
            ;;
    esac
done

(($#>1)) && warning "non-first argument(s) will be ignored: '${@:2}'"
file="${1:--}"

set -e

test -e "$SHAREDIR"/$name.xsl

if test "x$file" = x-; then
    file=$(mktemp)
    cat > $file
fi
output="$(xmlstarlet tr "$SHAREDIR"/$name.xsl "${parameters[@]}" "$file")"
if ((pretty)); then
    output="$(echo "$output" | xmlstarlet fo -s 2 -)"
fi
if ((diff)); then
    diff -u <(cat "$file" | if ((pretty)); then xmlstarlet fo -s 2 -; fi) <(echo "$output")
elif ((inplace)); then
    echo "$output" > "$file"
else
    echo "$output"
fi